High-tension switch



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Feb. 27 11934 c, G, KOPPHTZ HIGH TENSION swmm Filed May 29, 1929 2Sheets-Sheet i Tiiiiiii-----:---i|-liziitiiii-5-13-4 gjwwmtor Feh 2'7,1934?. c KoPPn'Z' HIGHEENSION SWITCH Filed May 29, 1929 2 Sheets-Sheet 2Patented Feb. 27, 1934 PATET: orrucr.

1,949,018 HIGH-TENSION swrron Carl G. Koppitz, Greensburg, Pa.,

assignor to Railway and Industrial Engineering Company.

Greensburg,

Pa., a corporation of Pennsylvania Application May 29, 1929. Serial No.307,014 11 Claims. (Cl. 200-48) The present inventionrelates to hightension switch mechanism, and more particularly to a high contactpressure switch which is adapted for direct exposure to atmosphericconditions.

The method employed for introducing the movable element into theswitchjaws and thereafter rotating the same to secure a high contact pressureis similar to the method employed in the switch construction describedin my prior Patent, No. 1,560,998, November 10, 1924. In my prior patentI have described a contact element of non-circular transversecross-section which is held in inclined position during the introductionof the non-circular element into the space between the switch jaws, thefinal closing movement of the switch eflfecting the rotation of thenon-circular element to bring its major dimension transversely of theswitch jaws.

An object of the invention is to provide a simple and relativelyinexpensive construction for effecting the introduction of a flattenedcontact element within a switch jaw, and thereafter rotating the contactelement to position the same transversely of the switch jaw. A furtherobject is to provide a high contact pressure switch in which the movableelements have the general form of a toggle linkage, the toggle linkagebeing adapted to position the contact element within the switch jaw, andto efiect relative angular movement of the contact element and theswitch jaw during the final closing movement of the switch.

These and other objects of the invention will be apparent from thefollowing description when taken with the accompanying drawings inwhich:

Fig. l is a side elevation of a disconnect switch embodying theinvention;

Fig. 2 is a front elevation of the same;

Fig. 3 is a side elevation of a rocker switch embodying the invention;and

Fig. 4 is a diagram of a switch jaw and reference planes and axes whichare referred to in the specification and claims.

In the drawings, the numeral 1 identifies a base plate of channel formupon which are mounted the insulator columns 2, 3, which carry therespective contact members of the switch. The customary metal cap 4 ofthe insulator 2 is provided with a plate 5 for receiving a terminal and50 with a contact lug 6 of soft metal which cooperates with the springarm 7 to provide the two parallel members of a switch jaw.

The insulator column 3 carries blade 8 for connection to a line terminaland a lug 9- upon which are pivotally mounted the straps 10 which formthe switch blade. The upper ends of the straps 10 are connected by abolt 11 which provides a pivotal support for the lower end of a contactarm 12 which terminates in a flattened contact element 13. The contactarm is provided with the usual apertured lug 14 for receiv= ing the endof an operating rod, and a spring 15' is connected between the parts 10.and 12 for nor= mally retaining the linkage in the broken position whichis shown in dotted lines in Fig. '1. To limit the relative angularmovement of the links 10, 12 of the toggle linkage, the parts areprovided with cooperating stop members 16', 17, respectively. v I v Theoperation of the switch will be apparent W from Fig. 1. When upwardpressure is applied to the operating lug 14, the blade and contact arm12 move as a unit about the lug 9 until the flattened contact head 13engages the contact member 6 of the switch jaw. The continued ap titplication of the upward pressure causes the toggle linkage to flattenand the spring 15 yields to permit the combined sliding and rotary movement of a flattened contact 13 within the switch jaw. The maximumdimension of the contact an element 13 is so chosen, with reference tothe transverse width of the switch jaw, that the contact element istightly wedged between the oppo-= site sides of the jaw when the switchmembers occupy their final position, as shown in Fig. 1. The exact formof the flattened contact element is subject towide variation. Theessential requirement is that the contact element shall have suchcross-section, on planes normal to its axis which is parallel to theaxis of the pivotal support 11, that the width of the projection of theelement upon thebasal plane of the jaw varies with the angularadjustment of the element about the pivotal support 11.

The location of the plane which I have designated as the basal planewill be apparent from Fig. 4, which is a perspective view of a simpleswitch jaw formed by bending the ends A of a metal strap at right anglesto the central or base portion B of the strap. As indicated by the toolegends on this view, the basal plane includes the base 13 and is normalto the longitudinal axis of the switch jaw; the medial plane of the jawis that plane through the longitudinal axis which is parallel to thejaws A. and the transverse plane passes through the longitudinal axisand is nor mal to the basal and medial planes.

Whilethe switch jaw formed by the soft metal contact 6 and spring arm 7difi'ers substantially from the simplified jaw structure shown in Fig,no

- tion of the contact element about an axis parallel'to the medial axisof the jaw. The combined rotary and sliding movement of the elementprovides acleaning action which ensures good'electricfal cbntact'. Thespring arm 7 may be formed ofstainless iron, spring steel or the likeand the "pressure exerted upon the contact arm varies in accordancefwiththe size and ampere rating of the switch. The contact element 13 isformed of relatively hard metal of lower'thermal and electricalconductivity than the contact 6, suitable metals being phosphor bronzeand soft copper respectively. With contact pressures of several hundredpounds and exceedingly small contact areas, heavy current densities arepossible when one of the contact elements, such as contact 6, has highelectrical and thermal conductivity. As explained in applicantscopending application, the contact area is only a small fraction of asquare inch, hence with a contact pressure of the order of 25 to poundsa pressure of 20,000 to 30,000 pounds per square inch is obtainable.With such a unit pressure, a current of several hundred arrlperes,having a current density of several thousand amperes per square inch,may be carried with safety.

, As shown in Fig. 3, the switch contact block. 18 and cooperatingspring arm 19 are carried by a flxed insulator column 20, and theoperating mechanism is carried by the rocking insulator column 21 andfixed column 22. The contact blade 23 with its flattened contact element24 is pivoted upon the arm 25 which, in turn, is pivoted upon lug 26mounted on the rocking column 21. The contact element 23 and arm 25cooperate to form a floating toggle linkage, the relatively fixed end ofarm 25 being connected by a link 27 to the top of the fixed insulatorcolumn 22. When the switch is open, as shown in dotted lines, the togglelinkage is in the flattened position and stop members 28 29 are providedon blade 23 and arm 25, respectively, to retain the parts in suchangular relationship that the contact element 24 will strike the lowerend of contact 18 as the column 21 is rocked towards the left to closethe switch. After element 24 engages the contact block 18, the furthermovement of the rocker insulator breaks the toggle linkage, carrying'theelement 24 into the switch jaw and simultaneously rotating the elementwithin the jaw.

In both types of switches, a relatively small movement of the contactelement corresponds to a relatively darge angular movement of theoperating mechanism during the final closing and inital opening movementof the switch. This decided mechanical advantage in the operatingmechanism makes possible high contact pressures with relatively smalloperating forces and, upon opening of the switch, insures heavy forcesfor dislodging ice which may have formed in the contacts.

It will be understood that the invention is not limited to thespecificconstructions herein described and illustrated since various forms ofsupporting and operating. mechanism may be designed for producingrelative translatory motion of a switch jaw and flattened contactelement to insert the element within the jaw and thereafter rotate theelement about an axis parallel to the medialaxis of the jaw to effect ahigh toggle linkage supporting said jaw and element for relativetranslatory motion, said contact element being so positioned on saidsupporting means that it enters between the said substantially parallelsurfaces of the switch jaw with the plane of its major dimensioninclined to the basal and medial planes of said jaw, and means foractuating said toggle linkage to translate said element into said jawand for effecting simultaneously with the flnal period of saidtrans1atory motion, relative rotary motion of said jaw and element aboutan axis parallel to the medial axis of said jaw the bondaries of saidflattened contact element adjacent said jaw being convex surfaces,whereby the areas of contact with said jaw are of the order of linecontacts.

2. In a switch of the high contact pressure type, a switch bladeterminating in a flattened contact member of T-shape and with the headthereof arranged transversely of the axis of the blade, a switch jaw,and operating means including a toggle linkage for effecting relativetranslation of said blade and jaw to carry the head of saidcontact'member through the mouth of and into position within saidjaw,said operating means being effective upon further operation thereof toproduce relative rotation of said contact member and jaw about an axis.parallel to the medial axis of said jaw to position the head of saidT-shaped contact member transversely of said jaw, g

3. In a switch of the high contact pressure type, a pair of contactmembers comprising a switch jaw and a flattened contact element havingan enlarged T-head of a width greater than the mouth of said jaw, meansincluding a toggle linkage supporting said members for relativetranslatory motion to carry the T-head of said element through the mouthof said jaw and inclined to the medial plane of said jaw, and operatingmeans for continuing the relative translatory motion of said togglelinkage after said element enters said jaw, to effect thereby relativerotary motion of said members to position said element transverse to themedial plane of said jaw, and to effect wiping engagement between saidcontact element and the cooperatin surfaces of said jaw.

4. A disconnecting switch for an electric circuit including a pivotedinsulating column having a T-shaped hinged contact member thereonconnected by a flexible conductor to the electric circuit, a secondinsulating member having a U-shaped contact member thereon cooperatingwith the first said contact member by pressure 1 engagement when theswitch is in closed position, andan operating mechanism adapted toactuate the said pivoted insulator column to closed and to openpositions.

5. A disconnecting switch for an electric circuit including an insulatorcolumn, a T-shaped hinged contact member supported thereon, a secondinsulating member having a U-shaped contact member thereon, and togglemechanism adapted to move said members into and out of pressureengagement.

6. The invention as set forth in claim 5, wherein said toggle mechanismefiects relative movement of said members to position the head of saidT-shaped contact within said U-shaped contact upon closing movement ofsaid mechanism and to thereafter effect relative rotation of saidmembers to wedgesaid head transversely of said U-shaped contact duringthe final closing movement of said mechanism.

7. In a high pressure contact switch, a switch jaw defined bysubstantially parallel surfaces, a contact element of T-shape with thehead thereof arranged transversely of the axis of the contact element, apair of insulators, means mounting the jaw on one insulator, meanspivotally mounting said contact element on the second insulator, meanssupporting the second insulator for .tilting movement about an axisparallel to the medial axis of the jaw, and operating means for tiltingsaid second insulator to position said T- head freely within said jawand then to continue said tilting movement to effect relative rotationof said T-head within said jaw.

8. In a high pressure contact switch, a switch jaw defined bysubstantially parallel surfaces, a contact element having a flattenedhead arranged transversely of the axis of the contact element, theflattened head having a transverse dimension greaterthan the normalopening of said jaw, a member carrying said contact element, meanssupporting said jaw and member for relative translatory movement in thetransverse plane of the jaw, means pivotally mounting upon said memberthat end of said contact element which is remote from the flattenedhead, means yieldingly retaining said contact element in such positionupon said member that the flattened head may enter freely within saidjaw, and operating means for effecting relative translatory movement ofsaid member and jaw to position said flattened head within said jaw andthereafter to effect relathereof, said elements being so positioned onsaid supporting means that the head of said 1'- shaped element will beintroduced into the jaw element with the plane of the major dimension ofsaid head inclined to the medial plane of said jaw element, andoperating means for actuat ing said toggle mechanism to introduce saidcontact element within said jaw element and then to effect relativerotation of said jaw and contact elements about an axis parallel to themedial axis of said jaw element, thereby to position said contactelement wholly within said jaw element and with the plane of its majortransverse dimension substantially normal to the contact surfaces ofsaid jaw element.

10. In a high pressure contact switch, a switch jaw having substantiallyparallel members, a flattened contact element having a pair of convexcontact surfaces for engagement with said jaw members, said contactelement having the plane of its greatest transverse dimension passingthrough said convex contact surfaces, and a toggle linkage supportingsaid contact element for movement into and out of said jaw, said contactelement being so supported on said toggle linkage that said elemententers said jaw freely before the toggle linkage completes a closingmovement v of the switch and is thereafter rotated into wedgingengagement with said jaw members by continued movement of said togglelinkage.

11. In a high pressure contact switch, the combination with a contactelement comprising a body member having a plane surface constituted by asoft metal of high electrical and thermal conductivity, and a resilientmember spaced from and extending parallel to said plane surface, of acontact element comprising an arm having a fiattened head provided withopposed convex surfaces for engagement with said jaw members, saidcontact element being formed of a relatively hard metal, and togglemechanism for introducing said contact element into said jaw prior tothe final movement of said toggle mechanism to close said switch, saidcontact element being so positioned on said toggle mechanism that finalclosing movement thereof rotates said contact element to carry theconvex surfaces thereof into wedging engagement with said jaw members.

" CARL G. KOPPITZ.

